Here is what I mean about tracking. Its easy to mess this up with a trolling motor mounted transducer, but any current or wind from the side will do the same thing even when running on the main motor.

The first image is how your sideview "cone" will look as you travel sideways to your direction of motion. Imagine you are driving between two underwater targets while the transducer or boat is skewed to the direction of travel - Heading does not match COG.



skew1.jpg


The second is how it gets drawn on the screen. The position and shape of the targets get distorted. Thats because the sideview "cone" on the left hits the left square before it hits the right square. It also hits the corner of the squares first. In addition, the distance from the boat will be off - all targets will look further away than they really are. Sideview distances are never correct, but this situation makes it even worse.

All of that adds up to distorted images that dont show up in the correct places.

The greater the angle of sideways motion, the worse the distortion is.

skew2.jpg